Though the selection of text is a bit scant at the moment, this app has some serious potential.  Duobook allows you to alternate between reading a story and having it read to you.

The only real impediment to use in a classroom is that one must create an account via a phone number.  This could potentially complicate the use of the app in a K-8 classroom as I’m unsure at this point the maximum number of devices one (the teacher) can be logged into at once.  In addition, the stories have to be downloaded which could present issues for 16gb devices.

Overall, it’s a solid product that would only get better with more offerings, especially those geared toward early readers.